<!DOCTYPE HTML>
<html>
<body>
<canvas id="myCanvas" style="border:1px solid;" width="300" height="150">
</canvas>
<script type="text/javascript">
var c=document.getElementById("myCanvas");
var context=c.getContext("2d");
for(var i=0;i<15;i++){ 
    context.strokeStyle="#FF00FF";
    context.beginPath();
    context.arc(0,150,i*10,0,Math.PI*3/2,true);
    context.stroke();
}
</script>
</body>
</html>

